Virtual reality (VR) and augmented reality (AR) applications have become more and more popular. Virtual reality typically refers to computer technologies that use software to generate realistic images, sounds and other sensations that replicate a real environment, or create an imaginary setting, and simulate a user's physical presence in this environment, by enabling the user to interact with this space and any objects depicted therein using specialized display screens or projectors and other devices. Virtual reality equipment usually includes a headset that may be arranged on the user's head. The headset holds a display in position in front of the user's eyes and in some cases provides loudspeakers for generating a suitable sound experience. Often, VR headsets are combined with standard headphones. Most headphones available on the market today produce an in-head sound image when driven by a conventionally mixed stereo signal. “In-head sound image” in this context means that the predominant part of the sound image is perceived as being originated inside the user's head, usually on an axis between the ears. If sound is externalized by suitable signal processing methods (externalizing in this context means the manipulation of the spatial representation in a way such that the predominant part of the sound image is perceived as being originated outside the user's head), the center image tends to move mainly upwards instead of moving towards the front of the user. While especially binaural techniques based on HRTF filtering are very effective in externalizing the sound image and even positioning virtual sound sources on most positions around the user's head, such techniques usually fail to position virtual sources correctly on a frontal part of the median plane (in front of the user).
This means that acoustic events from the front, which is arguably the most important direction for VR environments and AR applications, currently cannot be reliably reproduced at the correct position when played over commercially available headphones. Generally, the visual content of VR or AR applications may help to improve frontal localization. However, visible sound sources for all sounds in front of the user are not necessarily present in VR and AR applications. In some embodiments of the present disclosure the localization of sound sources in front of the user may be improved if combined with suitable signal processing. Besides the optimization of spatial sound aspects for VR and AR applications, ease of use and wearing comfort are further important factors for VR and AR headsets. Loudspeakers that are integrated into VR and AR headsets generally help to prevent the clutter that may result when two devices are worn on top of each other (VR/AR headset and headphones). Current arrangements that try to integrate loudspeakers into the VR/AR headsets suffer from a degradation of special sound aspects, especially perceived source direction and limited low frequency output. In order to avoid the degradation of localization performance, an individual compensation of the transfer functions between the loudspeakers and the ears may be used for each user. The proposed sound source arrangements do not require individual transfer function compensation and, therefore, can avoid the corresponding measurement procedure as well as measurement hardware.